Cleaning apparatus



2 Sheets-Sheet 1 Fig 3 1. 0. WALLB ERG CLEANING APPARATUS Filed July 1, 1946 Nov. 25; .1947.

Fig. 2

'Nov. 25, 1947.

l, o. WALLBERG CLEANING APPARATUS Filed July 1, 1946 2 Sheets-Sheet 2 630 IINVENTOR.

IVOR 0. WALLBERG 26a 25b 26b v A TTOR/VE Y Patented Nov. 25, 1947 UNITED STATES PATENT OFFICE (Granted under the act of March 3, 1883, as amended April 30, 1928; 370 0. G. 757) 7 Claims.

This invention relates to a cleaning apparatus directing a cleaning substance against the articles as they are carried on the conveyor,

Objects of this invention are to provide a cleaning apparatus for continuously conveying articles to be cleaned and directing a cleaning substance against the articles; to provide for directing high velocity abrasive against articles to be cleaned; to provide for revolving and simultaneously rotating a plurality of articles such as spark plugs past a group of sandblast nozzles; and to provide an apparatus of the class described having new and improved conveyor means, loading means, and abrasive handling means.

In accomplishing these and other objects of the present invention, I have provided improved de tails of structure, the preferred form of which is illustrated in the accompanying drawings, where- Fig. 1 is a side elevation view, partly in crosssection,'of a cleaning apparatus embodying the features of the present invention, partially broken away to shOW certain details of structure;

Fig. 2 is a full size side elevational view, partly in cross-section, of a spark plug in position on the conveyor of the apparatus of Fig. 1.

Fig. 3 is a detail vertical cross-sectional view of abrasive circulating tubes of the device of Fig. 1 illustrating the flow limiting means and the auxiliary air supply; when both plugs are on the carrier 20. 4

Fig. 4 is a plan View, partially broken away, of the apparatus of Fig. 1;

Fig. 5 is a front elevational view, partially broken away, of the apparatus of Fig. 1;

Fig, 5a is a fragmentary schematic diagram of the electrical circuit for the solenoid used to load spark plugs onto the conveyor.

Fig. 6 is a detail cross-sectional view of the nozzle used in the apparatus of the present invention;

Fig. '7 is an enlarged plan view of the nozzle of Fig. 6;

Fig. 8 is an elevation view of the nozzle arrangement of this invention taken from the point of view of a spark plug in position to be cleaned.

Referring more particularly to the drawing:

Numeral l0 indicates generally a base or housing of metal in the form of a substantially closed container having a power source such as an electric motor H installed in the bottom thereof. Through a chain and sprocket arrangement I2 and bevel gear train 13, the motor is adapted to rotate a drive shaft M. The shaft l4 extends vertically through a seal IS in an inclined partition 16 in the housing and then through a bearing ll into the upper region of the housing Iii. A roller driving wheel I8 is fixed to the shaft 14 adjacent its upper end. A bearing collar l9 on the shaft [4 supports a continuous conveyor 20 for articles to be cleaned. The conveyor 20 is freely rotatable about shaft l4.

The conveyor illustrated is designed to carry aviation spark plugs although it can be adapted within the scope of the invention to carry various articles. It comprises a cylindrical drum 2i having a lower flange 22, provided with a plurality of vertically extending U-shaped guide members 23 adapted to guide the lower ends of spark plugs, and having an upper flange 24, provided with a plurality of uniformly spaced radially extending fingers 25 for supporting spark plugs.

As shown most clearly in Fig. 2, each spark plug 26, before insertion into the cleaning machine, is provided with a cap 2'! for protecting its lower opening and lower threads 28 from the action of the cleaning substance. The cap 2'? is provided with a threaded portion 29 of limited extent to facilitate rapid application and removal of the cap. The lower end of the plug 26 covered by the cap 21 is received in and guided by the curved member 23 as the plug is rotated in a manner hereinafter described. 7

The threads 39 on the upper end of the spark plug are protected from abrasive by a generally cylindrical shield 3|, Fig. 2, having a short internal thread 32 for quick coaction with the threads 30. The shield 3! also serves to facil tate the support of the spark plug on the conveyor by virtue of a flange 33 formed thereon, the undersurface of which an adjacent pair of fingers 25 engages on opposite sides of the plug. The fingers 25 fit fairly snugly between the undersurface of the flange 33 and the upper surface of a flange 34 formed on the plug 26 and are so spaced that each finger simultaneously supports one side of each of two plugs. For example, the finger 25a in Fig. 4 supports one side of plug Zea and one side of plug 261).

The shield 3| is open at its upper end exposing the electrodes 35, Fig. 2, of the spark plugs to the cleaning action of the machine. A substantially cylindrical external surface 36 of the shield 31 serves as a tire or rim for the spark plug to facilitate rotation of the plug from frictional contact with friction elements hereinafter described.

Fixed on the periphery of the roller drive wheel of the plug shields 3i.

' ing in such a position as to frictionally engage the radially outward portion of the surface The cylindrical shields 55 may thus be said to be roughly externally tangent to the cylindrical roller surface 3? and. internally tangent to the arcuate member 38, which latter forms a track on which the plugs rotate as they are revolved by the action of the driving wheel It.

The spark plugs are cleaned as they are carried on the conveyor by means of a plurality ofjets of cleaning substance directed against them by a plurality of nozzles 3%. The cleaning substance used is preferably an abrasive such as sand, although liquids, liquid suspensions of abrasive, etc. could: be used. The abrasive is stored in a hopper 38, Fig. 1, and flows into the nozzles 35 through conduits M and 42. After being emitted by the nozzles 39 to clean the spark plugs, the abrasive drops down onto the inclined partition l and slides down it tothe bottom $3 of a belt or chain conveyor housing 43 joined by fiuid tight connections to the main housing it. A belt or chain conveyor 45, driven b motor H and having buckets or scoops 45, picks up the used abrasive at 43 and dumps it through a sieve or strainer 41 into the hopper 4'9. The tension on the belt conveyor can be varied by a-conventional adjustment 49. The sieve 41" is pivoted as at 50 about a horizontal axis and is held in the position illustrated in Fig. 1 by a spring (not shown). strikes an arm 5| formed on the strainer as apparent from the disposition of scoop l'ta in Fig. 1. This causes the sieve ll to pivot about axis 50 against the action of its restoring spring and thus jog the abrasive to "make it fall into the hopper at. An electric resistance heater 52 is provided to dry out the sand'to prevent clogging. A transparent window 53, Fig. 5, is provided to observe the operation of the belt conveyor 45 and the sieve ll.

A duct 5d communicating with the portion of the housing lO- above the partition It and with the belt conveyor housing 44 leads to an exhaust fan (not shown) which removes abrasive dust, foreign particles, and the like.

The nozzles 39 are disposed intwc groups generally indicated by the numerals 55 and 5'3, Fig. 8. The nozzles of group 55 direct jets of cleaning substance vertically downward against the electrodes of the spark plugs while the nozzles of group 55 direct jets of cleaning substance horizontally toward the lateral surface of the plugs. The nozzles of group 55 are arranged in banks, 51, 58, 59, and 65, preferably four in number. Each bank has a series of nozzles, preferably four in number disposed at an angleof preferably 45 to the horizontal, with the lowest nozzle of each series being directly beneath. the highest nozzle of the series to the left of it as viewed. in Fig. 8. For example, nozzle 352' of series: 58v is directly over nozzle 39h of series 57; Asufiicient number of nozzles 39 isprovided and they areso spaced as to subject each spark plug to a. substantially continuous stream of cleaning substance during at least two complete rotations thereof to insure adequate cleaning.

Although various types of nozzles 39 mayv be used in the cleaning apparatus of the present As'each scoop 46 passes the sieve 41 it 4 invention, the type illustrated in detail in Figs. 6 and 7 has proven particularly satisfactory. The nozzle is mad-e of an outer metal tube 6! joined by welding or other suitable means at 62 to a fluid supply manifold 63. The tube BI is bent as at 54 substantially at right angles forming an elbow. Adjacent the bend 64 a smaller metal tube 65- extends concentrically with' tlie outer arm of the elbow and terminates in an annular separating plate 61 fixed within the tube 5i at a point spaced somewhat from the outer end of the tube 6! to form a mixing chamber 63. The plate el'hasia plurality of uniformly spaced openings t9 drilled therethrough at an acute angle to the plate to produce a swirling motion in the chamber 58 of the fluid emitted through them. Abrasive, such as sand, is fed through the tube, preferably almost entirely under the action of gravity, at a slow speed just suiiicient to maintain a continuous flow. As: the abrasive leaves the outerend of the tube 65 at slow speed and: enters the chamber 68-, it is picked up by the swirling motion of the fluid, preferably compressed air, emerging from the openings 69* and is discharged as a high velocity air-sand mixture against the spark plugs.

The conduits ll and 42' for supplying abrasive to the nozzle groups 55- and 5-6, respectively, are shown in detail in Fig. 3. Each conduit 4! and 42 preferably includes a short metal tube 15' fixed to the bottom of the hopper 40,. a short length of rubber or other flexible tubing 7|, a second metal tube 72-, and a second rubber tube 13. The lower end of each tube 13 fits snugly over the metal tube 65 of" a nozzle 39. A small diameter metal tube i l enters the" tube 12 through its side wall and has one end bent to point downward as at 15. The tube 7c is brazed or otherwise joined to -tube 1 2* to make a fluid-tight joint. At its other end 76 the-tube M is connected to an auxiliary fluid or air supply manifold H. To reduce the flow of abrasive through the conduits to the desired rate, a plug or snubber 18 of metal or other suitable material may be inserted in the tube H The plug- 18 has a rol atively small diameter opening 79 therethrough. The opening '19 is conveniently chosen to be of such a size that it will just prevent the passage of sand under the action of gravity but will permit the flow as soon as the slightest auxiliary air pressure of perhaps /2 pound" per square inch is applied to the tube l4 to cause a reduction in pressure within the conduit adjacent the end 75 of the tube 14. The use of rubber tubes "H and 13 affords flexibility of operation in' that they provide for easily installing or removing a plug '19; provide forby-passing'the auxiliary air supply tov any particular nozzle, if desired,. and

provide for disconnect-ingany particular nozzle,

plied to the manifold 63a of the nozzle group 55 and. is indicated by. gage 82; Through a reducingvalve 83the manifold 63bfor nozzle group 55 is supplied'with lower' pressure air atabout 30 pounds per square inch, indicated by gage 84. This lower pressure, adequate for cleaning spark plug electrodes, is used to avoid damaging delicate mica insulation. For supplying low pressure air to the manifold l! a reducing valve 85 is provided. This valve 85 is set to introduce whatever slight pressure, hereinbefore described as about /2 pound per square inch, is necessary to just overcome the tendency of the abrasive to pack and stick in the conduits and thus per mit the flow of the abrasive substantially entirely under the action of gravity. The pressure in manifold I1 is shown on gage 85.

A loading mechanism is provided for automatically feeding spark plugs to be cleaned into the machine. This mechanism includes a track 91 fastened to the front of the machine by a bracket 98. The track 91 is provided with a pair of rails 89 partially inclined as shown at 99, Fig. 5, and turned at 90 at their lower ends terminating opposite and level with the fingers 25 as they are exposed in passing by a. break 9|, Fig, 4, in the arcuate friction member 39. The rails 89 support the spark plugs by engagement beneath the flange 33 on the shield 3| in the same manner as the fingers 25 support the plugs, and the rails are so disposed that as each pair of fingers 25 passes opposite them the fingers momentarily form a continuation of the rails. The plugs are inserted by hand at the upper end of the track 8'! and slide down it by gravity.

The plugs are periodically projected onto the conveyor by means of a shuttle 92, Fig. 4, overlying the track 91 at its turn and engaging the shields 3| on the plugs. As the shuttle 92 thrusts one plug into the machine, its side 93 prevents any additional plugs from sliding down the track 61. The shuttle 92 is operated in a known manner by a lever arm 94 pivotally connected at 95 to a link 95 pivoted at 91, Fig. 1, to a bracket 99 fixed to the base I9. The lever is actuated by a solenoid 99 having its plunger I99 pivotally connected at I91 to the lever arm 94. Current to the solenoid is controlled in a conventional manner by a switch 99a, shown schematically in Fig. 5a, periodically operated by each of the fingers 25 so as to synchronize the motion of the shuttle 92 with the motion whereby a plug is inserted between each pair of fingers 25 at the very moment it passes opposite the track 81.

A device for unloading plugs from the machine after they have been cleaned includes a curved cam member I92, Fig. l, fixed to the housing I9. As each plug reaches the end of its revolution on the conveyor the radially inward portion I93 of the surface of the cam member engages the radially inward surface of the plug, as shown in the case of plug 29a in Fig. Continued motion of the conveyor 29 causes the plug to be cammed radially outward until it is completely free of the fingers 25 of the conveyor, as illustrated in Fig. 4 in the case of plug 291). The plug may then drop down a chute, not shown, into any convenient receiver.

Operation To use the machine of the present invention the hopper 19 is first filled with an abrasive such as blasting sand. The air valves 8| and 83, are adjusted to provide the desired pressure indicated on gages 92 and 89 for cleaning the lateral surface and electrodes of the spark plugs to be cleaned, and the auxiliary air valve 85 is set to the pressure, indicated on gage 99, just suficient to produce a gravity actuated flow of sand through conduits GI and 92. The heater 52 is energized to maintain the sand dry to facilitate easy flow. The motor II is started, causing the drive wheel I9 to rotate and the belt conveyor 65 to operate. Shields and caps 21 are placed on the plugs 26, their quick placement being assured by the short threads 32 and 29, respectively. The prepared plug units are then placed on the inclined portion of the track 81, with the rails 89 engaging the fiange 39 on each plug unit.

In order to start the motion of the conveyor 29 one or more plugs may be inserted by hand between fingers 25. The conveyor mechanism then functions as a planetary friction gear system. The surface 31, acting as a driving sun gear, rotates the plugs 29, whose shields 9i serve as planet pinions and roll along as they react against the friction surface 29, which latter constitutes a fixed orbit gear. The resultant motion involves turning of the conveyor 29 about its axis in the capacity of a planet carrier. The plugs 29 thus rotate on their own aXes as they are revolved on the conveyor 29 about its axis. The motion of the conveyor 29 produces by means of fingers 25, periodic, synchronous operation of the switch (not shown) controlling solenoid 99. After the initiation of the switch operation the feeding of plugs to the machine becomes automatic through of the conveyor 29,

the action of the shuttle 92 actuated by the solenoid 99 through the linkage I99 and IE at the moment when each pair of fingers 25 forms a continuation of the track 9?.

The plugs 29 are carried on the conveyor 29 and perform at least two rotations on their own axes during the time they are passing the jets of air-driven sand issuing from the nozzle groups 55 and 59. This insures that all parts of the plugs are adequately exposed to cleaning action. As plugs complete their revolution on the conveyor 29, they are engaged by the fixed cam member W2 and ejected by its camming action from the conveyor into a convenient receptacle (not shown). The shield 3i and caps 21 are then removed for re-use.

The conveyor buckets d5 retrieve the used abrasive which ricochets off the spark plugs and slides down the inclined partition I9 into the trough 49. The buckets 49 dump the used sand and entrained foreign particles, such as paint cleaned from the plugs, into the screen or sieve 9?. As the buckets 95 pass the arm 55 they jog the sieve 4T sifting the sand back into the hopper 99 for re-use. The mesh of the sieve 4? is just sufiicient to permit sand to pass through it but to retain larger foreign particles.

The exhaust fan connected to the duct 54 withdraws, by suction, dust and light weight foreign particles from the housing I9. A large settling tank (not shown) into which the duct 59 empties, so reduces the .air speed that any abrasive picked up by the suction fan will settle and fall back into the trough 93.

Although the invention has been illustrated as applied to a particular type of spark plug it is apparent that it is equally applicable to cleaning other articles, either with or without shields or caps, and may employ cleaning substances other than air-driven sand.

While I have shown but one embodiment of my invention, it is apparent that the device is susceptible to modification without departing from the spirit of the invention. I do not wish, therefore, to be limited by the disclosures set forth, but only by the scope of the appended claims.

The invention described herein' may be manufactored and used by or for the Government of the United States of America for governmental purposes Without the payment of any royalties thereon or therefor.

I claim:

1. An apparatus for cleaning a plurality of articles, each having a cylindrical surface of substantially identical diameter, comprising a housin a generally cylindrical conveyor mounted for rotation about a substantially vertical axis within said housing and having a plurality of radially extending fingers uniformly spaced around the periphery'thereof,-each pair of said fingers being adapted to receive and support one of said articles,- a roller Wheel mounted for rotation about saidvertical axis having a frictional surface on its periphery adapted to-eng'a'gethe portion of said cylindrical surface of said articles radially inward relative to said vertical axis when said articles are carried by said conveyor, an arcuate reaction member having a friction surface concentric with said conveyor anclso positioned as to engage the portion said cylindrical surface of said articles radially outward relative to said axis, so constructed and arranged that rotation of said wheel causes revolution of said article with said conveyor and simultaneous rotation of each said articles about the axis of its cylindrical surface, said arcuate member having an interrupted portion exposing said conveyor for loading and unloading said articles; means for directing a cleaning substance against said articles as they are carried by said conveyor, means above-said directing means for storing cleaning substance and supplying said substance at least partially under the action of gravity to said directing means, and means including an inclined member beneath said conveyor for collecting and returning used cleaning substance to said storage means.

2; An apparatus for cleaning articles, each having an annular shoulder, comprising a conveyor having a plurality of uniformly spaced fingers, each two adjacent fingers being adapted to support one of said articles by engaging opposite sides of said shoulder; .aloading mechanism including a first track portion having rails adapted to support said articles by engaging opposite sides of the shoulders thereon, said conveyor fingers being movable past said trackportion and so disposed relative thereto that said each adjacent pair of fingers periodically forms a momentary continuation of said track, a shuttle adapted to push said articles along said track, an inclined track portion entering saidfirst track at a side thereof and adaptedto load. by gravity said first track with said articles, means for periodically actuating said shuttle in synchronism with the movement of said fingerspast said loading mechanism to'push said articles from said first track portion onto said conveyor between apair of adjacent fingers at the moment said fingers form a continuation of saidfirst track; means for cleaning said articles as they are carriedon said conveyor; and unloading means comprising a cam surface adapted to'cam said articles off said conveyor.

3. A cleaning apparatus for cleaning articles each having a cylindrical portion and provided with an annular shoulder comprising a sub-staritially closed housing-er generally cylindrical conveyor mounted for rotatioriabout a substantially vertical axis within said housing, article support means around the periphery of said conveyor in- 8 eluding uniformly spaced radial fingers adapted to receive said articles and support them by ehgagement with the shoulders thereon and spaced guides" to receive portions of said articlesrerifote from said shoulders c'oacting with said fing'ers'to' lllain Sadat-171016841 1 desired DESitiOll; an al'llit roller surface surrounding '9," portion of 'S'Etid 661i VE'YOI' and adapted to fricti'onally engage the 01211?- warn 8163 01 said' cylindrical 1561 11161 18 ($15 said a" threaded portion to be protected from clea n'g 'etion comprising a shield having a; substantially cylindrical external surface stepped to present a supporting shoulder and having an internal surface provided with a relatively short thread for rapid positioning of said shield by engagement with said threaded portion of said article and provided with a portion of a diameter substan tially larger than the outside diameter or said threaded portion adapted to surround an shield said threaded portion; a first friction member; a second friction member" movable r lative to said first friction member; a plurality of jetsof cleani ng material; and a carrier h'avingmeans forengaging' said supporting shoulder or said shield for denying said article with the external surface of said shield in frictional engagement With both said friction member's, whereby through relative motion of said members, said article is rotated as it is moved by relative motion of said members past said jets.

An apparatus for cleaning articles, saidafticlesbeing adapted to receive generally-cylindrical shields which constitutetherewith units" on which said shields form anrilllar'shollldeis, comprising a conveyor having a sub-stanuany hon"- z'ontaldis'o mounted for rotation about a substan tially vertical concentric aXi's, support means around the periphery of said cdriveyorimuunung uniformly spaced radial fingers for suspending said units from said snoumers; ari arb'liate fricnon roller-surface surroundin a", portion of said eoriveyorand adapted to be oontiguousto theolitward surface of said shields s'aid units are carried by said conveyor; a friction roller Wheel concentric With s'al'id' cdllVyOradafitd tohaIV its t peripherycontigiiou's to the'iriufard surface of said shields when said units are carried said cdfi v yor', whereby said articles may be rotated as they a e revolve cl by said conveyor; and means f or directing a cleaning substance against said? ar ticles as they are rotatingly'cofive'yed.

6. An apparatusfor cleaning'an afticlhavili an area to be protected from cleaningactioii' com: prising a shield adapted for'engagement with the article to surround the area to be protected, said shield'having a generally cylindricalexternal surface; a first triction member, a second friction member moveable relative to said first friction mer'ri "er, a carrier for said article disposed so as to ta-insaid external surface of said shield in frictional contact with: said frictionmembers whereby said article may ber'ota-ted by relative motionbetween said members. k

7. A cleaning apparatus comprising a conveyor for articles to be cleaned, nozzle means adapted to direct a fluid and abrasive mixture against said articles as they are conveyed, abrasive storage means disposed above said nozzle means, abrasive carrying tube means connecting said abrasive storage means with said nozzle means, flow limiting means within said tube means, fluid supply means entering said tube means between said flow limiting means and said nozzle means for assisting the flow of abrasive, means for drying said abrasive to limit clogging thereof, and compressed fluid supply means for said nozzle means.

IVOR O. WALLBERG.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 865,261 King et a1 June 21, 1887 1,875,994 Davis Sept. 6, 1932 1,918,653 Martin July 18, 1933 2,365,152 Stearman Dec. 19, 1944 FOREIGN PATENTS Number Name Date 789,684 France Aug, 26, 1935 

